The invention relates to a grate retort. In another aspect, the invention relates to retorting a material on a moving grate to recover hydrocarbon values.
Various mineral materials, such as oil shale, lignite, and tar sands contain hydrocarbon values. Retorting is one manner in which the hydrocarbon values can be recovered from the minerals in a more usable liquid or gaseous form. One type of retorting system utilizes a traveling grate to transport the material through a retorting zone. The material is generally subjected to several other steps in addition to retorting for reasons of economy. Usually, residual carbonaceous material remaining on the residue from the retorting step will be burned off to form hot combustion gases and hot particulate residue. The combustion gases are conveyed to some other heat requiring step. The hot particulate residue is usually cooled prior to being discharged and the hot gases formed in cooling the residue are conveyed to some other heat requiring step. Recovery of the hydrocarbon values from the mineral matter as a high value product and maximizing exploitation of the residual energy value of the mineral matter is an area of extensive research.